Related papers: Direct Measurement of the Spatial-Spectral Structu…
We investigate the astonishing physical aspects of Exceptional Points (EPs) in a 1D planar few-mode optical waveguide. The waveguide hosts four quasi-guided modes. Here interactions between the selected pair of modes are modulated by a…
When an optical pulse is focused into a multimode waveguide or fiber, the energy is divided among the available guided modes. Consequently, the initially localized intensity spreads transversely, the spatial profile undergoes rapid…
Photon-pair correlations in spontaneous parametric down conversion are ubiquitous in quantum photonics. The ability to engineer their properties for optimising a specific task is essential, but often challenging in practice. We demonstrate…
Continuous-variable encoding of quantum information in the optical domain has recently yielded large temporal and spectral entangled states instrumental for quantum computing and quantum communication. We introduce a protocol for the…
Entangled photons are pivotal elements in emerging quantum information technologies. While several schemes are available for the production of entangled photons, they typically require the assistance of cumbersome optical elements to couple…
Nanoscale generation of individual photons in confined geometries is an exciting research field aiming at exploiting localized electromagnetic fields for light manipulation. One of the outstanding challenges of photonic systems combining…
Stimulated emission tomography (SET) is an excellent tool for characterizing the process of spontaneous parametric down-conversion (SPDC), which is commonly used to create pairs of entangled photons for use in quantum information protocols.…
When an optical pulse is spatially localized in a highly multimoded waveguide, its energy is typically distributed among a multiplicity of modes, thus giving rise to a speckled transverse spatial profile that undergoes erratic changes with…
It is known that photon pairs generated from pulse-pumped spontaneous parametric processes can be described by independent temporal modes and form a multi-temporal mode entangled state. However, the exact form of the temporal modes is not…
We experimentally analyze the complete photon number statistics of parametric downconversion and ascertain the influence of multimode effects. Our results clearly reveal a difference between single mode theoretical description and the…
We demonstrate generation of high-purity photon pairs at 1560 nm in a single spatial mode from a periodically-poled KTiOPO_4 (PPKTP) waveguide. With nearly lossless spectral filtering, the PPKTP waveguide source shows approximately 80 %…
We study the generation of biphoton modally entangled states in such waveguide structures that lead to spectrum broadening. The process of spontaneous parametric down conversion (SPDC) has been considered for the biphoton generation. The…
A theoretical study of the performance of single-mode coupled spontaneous parametric downconversion sources is proposed, which only requires very few assumptions of practical interest : narrow-bandwidth and quasi-degenerate collinear…
The ability to generate quantum entangled photon pairs through spontaneous parametric down conversion (SPDC) is playing a pivotal role in many applications in quantum technologies, including quantum communications, quantum computation, and…
We have developed a rigorous quantum model of spontaneous parametric down-conversion in a nonlinear 1D photonic-band-gap structure based upon expansion of the field into monochromatic plane waves. The model provides a two-photon amplitude…
Analytical expressions are derived for the distribution rates of spatial coincidences in the counting of photons produced by spontaneous parametric down conversion (SPDC). Gaussian profiles are assumed for the wave function of the idler and…
Spontaneous parametric down-conversion (SPDC) in subwavelength nanostructures is a promising source of quantum light, owing to its multifunctionality and ability to generate complex quantum states. Nevertheless, the mechanisms governing…
We theoretically investigate the quantum scattering of a single-photon pulse interacting with an ensemble of $\Lambda$-type three-level atoms coupled to a one-dimensional waveguide. With an effective non-Hermitian Hamiltonian, we study the…
We measure the next-nearest-neighbour coupling in an array of coupled optical waveguides directly via an integrated eigenmode interferometer. In contrast to light propagation experiments, the technique is insensitive to nearest-neighbour…
Characterization and analysis of spin-orbit coupled (SOC) states, as a measurement problem, play a vital role in research on the modern optics and photonics based on structured light. Here, we demonstrate determination of photonic SOC…